In-Vivo Sensing Device With Detachable Part

ABSTRACT

A device and system for in-vivo sensing having a relatively heavy part and a relatively light part such that the heavy and light part may be temporarily attached in-vivo. Detachment of the heavy part may be provided at a predetermined location along a body lumen. The light part upon detachment of the heavy part may for example float within a body lumen.

FIELD OF THE INVENTION

The present invention relates to the field of in-vivo sensing.Specifically, the present invention relates to a floatable in-vivosensing device with a detachable part.

BACKGROUND OF THE INVENTION

An in-vivo device such as an ingestible sensing device may be used forsensing in-vivo conditions in cavities or body lumens such as forexample the gastrointestinal (GI) tract. Parameters that may be sensedor detected include for example temperature, pH, pressure,electroconnectivity, etc. In-vivo imaging devices may be used forimaging of body lumens such as the GI tract. For example, an ingestiblecapsule including a sensor, such as an image sensor, may be ingested andmay move through the small intestine by peristalsis while imaging orotherwise sensing the small intestine. However, passive movement ofobjects such as for example imaging sensors, such as by way ofperistalsis through larger body lumens, such as the large intestine, maybe slow and unpredictable and may not facilitate proper imaging of suchlarger body lumens.

The large intestine or colon, whose main function is to remove much ofthe water from the stool and to store the stool, begins with the cecum,a small saclike evagination, then continues with the ascending colon,from the appendix in right groin up to a flexure at the liver,transverse colon, liver to spleen, descending colon, spleen to leftgroin, then sigmoid (S-shaped) colon back to midline and anus. The colonhas three longitudinal muscle bands whose actions assist movementthrough the colon.

SUMMARY OF THE INVENTION

Embodiments of the invention describe an in-vivo sensing device that maybe for example floatable or have a certain buoyancy or specific gravityin some parts of a lumen and be non-floating or have a certain otherbuoyancy or specific gravity in other parts of the lumen. The in-vivodevice may have a floatable and/or relatively light part and/or anon-floatable and/or relatively heavy part that may be temporarilyattached. In a part of the lumen where it may be desirable for thein-vivo device to have floatable qualities the light part and the heavypart of the in-vivo device may disengage. In some embodiments of thepresent invention, the disengagement may initiate a component in thein-vivo device to activate. In other embodiments of the presentinvention one or more sensors may be used to detect the position alongthe lumen where it may be desirable to disengage the light and heavypart of the in-vivo device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description taken in conjunction with thedrawings in which:

FIG. 1 is an illustration of an in-vivo sensing system with an in-vivodevice having a detachable heavy part and a light part in accordancewith an exemplary embodiment of the invention;

FIG. 2 is a schematic illustration of an area of an in-vivo sensingdevice where a heavy part and a light part of such device may beconnected in accordance with an exemplary embodiment of the invention;

FIG. 3 is a schematic illustration of an in-vivo device with a switchand a detachable part in accordance with an exemplary embodiment of theinvention;

FIG. 4 is a schematic illustration of an in-vivo device with at leastone sensor, a switch and a detachable part in accordance with anexemplary embodiment of the invention; and

FIG. 5 is a flowchart schematically illustrating a method for in-vivosensing of a lumen, according to an embodiment of the invention.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

According to some embodiments of the present invention, there may beprovided an in-vivo sensing device that may be configured to for examplealter configurations so that at a particular times or in particularareas or body lumens, such as for example the small intestine, thedevice may be or include a substantially floating or buoyant device,while at other times or at other areas or body lumens such as forexample parts of the large intestine, the device may be a substantiallynon-floating device.

A substantially floatable or floatable in-vivo sensing device may floatin or be carried by liquids and/or bodily fluids in for example a bodylumen. For example, in one embodiment, the liquid contained in a bodylumen, such as a GI tract, may have a specific gravity of approximatelyone, and thus a floatable device or portion of a device may have aspecific gravity of less than one. In other embodiments, the specificgravity of the liquid and/or bodily fluid contained in the body lumenmay be greater or less than one and the specific gravity of thefloatable device may be less than the specific gravity of the liquidcontained in the body lumen. Such sensing device may be useful insensing, such as by imaging, lumens containing or capable of containinga bulk of liquid. One example of such a lumen may be the large intestineor colon. A floatable sensing device may, for example, be carried by theliquid in the large intestine and may thus be moved through the lumentogether with the bulk of liquid.

It may be advantageous to move objects through a body lumen, forexample, the colon independently of the natural action of the body lumenmuscles. For example, delivery of a medicament to a specific location inthe colon may be time dependant, such that the natural movement in thecolon may not be sufficiently reliable to deliver such medicaments ontime. Also a device for imaging the colon might benefit from beingmoved, such as by way of floating, through the colon so as toefficiently view the colon.

While a floating in-vivo sensing device may be useful in lumens with abulk of liquids such as for example in certain parts of the colon, afloating in-vivo sensing device may be less than optimal for sensing ofother areas of the GI tract, such as for example the small intestine.Furthermore, a floating in-vivo sensor may typically traverse the GItract relatively slowly. Thus, an internal power supply (e.g., abattery) may be depleted before the floatable sensor may reach the endof the GI tract.

In some embodiments, a sensing device in accordance with an exemplaryembodiment of the invention may be an ingestible sensing device.Embodiments of an ingestible imaging device may be described in U.S.Pat. No. 5,604,531 to Iddan et al. and in U.S. application Ser. No.09/800,470, entitled “A Device And System For In-vivo Imaging”, file on8 Mar. 2001, both of which are assigned to the common assignee of thepresent application and incorporated herein by reference. Embodiments ofa floatable sensing device are described in U.S. patent application Ser.No. 10/150,492, which was published under the publication number20030018280 on Jan. 23, 2003 and which is assigned to the assignee ofthe present invention and which is hereby incorporated by reference.Various embodiments of the present invention may use or may be used withdevices and methods, such as imaging and/or receiving devices andmethods, as described in U.S. Pat. No. 5,604,531 and/or U.S. Ser. No.09/800,470 and or US 20030018280, however other embodiments may usemethods and have structures not found in these references.

Reference is now made to FIG. 1, an illustration of an in-vivo sensingsystem with an in-vivo device having a detachable relatively heavy partand a relatively light part, in accordance with an exemplary embodimentof the invention. Device 10 may be a sensing device such as for examplean autonomous in-vivo imaging device. In some embodiments device 10 mayinclude for example other sensors instead of or in addition to animaging sensor, such as for example a temperature sensor, a pH sensor, apressure sensor or an electrical conductivity sensor. Other sensors arepossible. For example, a motion detector may be included in device 10for determining, for example, when the device may be in motion; externalmotion detection may be used as well.

In some embodiments device 10 may include for example an optical and/orviewing window 21 and an imaging system for obtaining image data frominside a body lumen. The imaging system may include for example one ormore illumination sources 23, such as for example a white LED or anotherillumination source that may illuminate in another color or use someother electromagnetic frequency. Device 10 may for example include animager such as, for example, an imager 24, which may detect images, andan optical system 22, which may include, for example, a lens and a lensholder, which may for example focus images onto, for example, the imager24. In one embodiment, imager 24 may be a CMOS imager, however, othertypes of imagers such as for example a CCD or other imagers may be used.Illumination source 23 may illuminate for example a body lumen throughoptical window 21. Device 10 further may include circuitry such as forexample an ASIC transmitter 26 and an antenna 27 that may for exampletransmit signals, and a power source 25, such as for example silveroxide batteries, that may for example provide power to the electricalelements of device 10. Signals that may be transmitted by for exampletransmitter 26 may include video, still images, temperature, pH or othersensory data as may be collected by device 10. In some embodiments ofthe present invention transmitter 26 may include control circuits forcontrolling one or more functions of device 10. In other embodimentsdevice 10 may include a receiver 28 for receiving external commands orsignals. In some embodiments of the present invention the receiver 28may and transmitter 26 may be integrated into a transceiver.

Device 10 may be shaped, for example, as a cylinder with convex ends, asa sphere or in other shapes or dimensions as may be suitable for passagein or through a body lumen. Device 10 may in some embodiments be shapedas an oval or capsule. Other shapes may be used.

In some embodiments, device 10 may be configured for example in two ormore lobes or parts, which may be, for example, releasably held togethersuch that such parts may be detached for example under certainconditions, upon the occurrence of certain events, or upon sensing oneor more parameters for example that may be above a determined threshold.One of such parts may for example be a floating, buoyant or light part12 and another may be a non-buoyant or heavy part 30. In someembodiments, the terms light and heavy may be relative terms withrespect to buoyancy and not necessarily with respect to the absoluteweight of a light part 12 as compared to a heavy part 30. In someembodiments the relatively light part 12 may be releaseably connected tothe relatively heavy part 30 so that heavy part 30 may be detachablefrom light part 12. In some embodiments, light part 12 may include orcontain some or all of the device's 10 active or functional components,for example, components that may be required for in-vivo sensing, e.g.possibly including optical system 22, ASIC transmitter/controller 26,power source 25 and antenna 27, such that for example light part 12 maybe self contained, being capable of performing sensory and transmittingfunctions after it detaches from heavy part 30. The specific gravity forlight part 12 may be reduced, for example to a specific gravity lessthan the specific gravity of bodily fluids present in a body lumen, by,for example, providing a volume of empty space, by for exampleincreasing the volume of light part 12 above the minimal volume requiredto enclose the elements incorporated within the housing of light part12. The additional volume may be dispersed between the components orconcentrated in the central area of light part 12 or may be concentratedbetween the viewing dome 21 and the image sensor 24, or in othersuitable areas. In one embodiment, an additional volume may beincorporated by elongating cross-section area of device 10 so as tocreate an elliptical cross-section and thus increase the cross-sectionalarea and volume of light part and/or device 10 so as to reduce thespecific gravity of light part 12. A device, such as a capsule with anelliptical cross-section may be easier to swallow than a device with asimilar volume having a circular cross-section. In some embodiments,heavy part 30 may also include for example one or more componentselectrical or otherwise, for example sensors 33 such as for example animager, a pH sensor, a thermometer or other sensor, a power source 32such as for example a battery or other components, so that heavy part 30may for example perform sensing functions before or after it detachesfrom light part 12 or independently of light part 12. In someembodiments sensor 33 may be linked by for example wires 35 or othercircuitry or by wireless electrical communication to the ASICtransmitter/controller 26 and antenna 27 of light part 12 so thatsensory data collected by heavy part 30 may be transmitted throughantenna 27 while heavy part 30 and light part 12 may be attached, forexample, temporarily attached. In some embodiments, heavy part 30 mayinclude a transmitter and circuitry 34 so that it may broadcast sensorydata, for example, after it may be detached from light part 12.

Heavy part 30 may be configured to have on its own or together with orwhen connected to light part 12 a specific gravity above the specificgravity of the in vivo body lumen liquid, or for example above 20percent more, and/or a specific gravity that may renders it at leastsubstantially non-floatable in for example an in-vivo environment.Typically, according to some embodiments of the inventions when heavypart 30 may be connected to or temporarily attached to light part 12,device 10 may generally not be buoyant or floatable in water or otherfluids as may be present in for example a body lumen such as for examplethe GI tract. Heavy part 30 may, in some embodiments, be weighted withone or more ballast(s) or weight(s) 31 of for example metal, plastics orsome other suitable material or may for example have a thicker shell ormay be solid part. The size of heavy part 30 may in some embodiments beup to approximately one third the size of device 10, though other sizesand ratios may be possible. Heavy part 30 may have specific gravity thatis other than the specific gravity of light part 12.

Light part 12 may be weighted or configured to have a specific gravityof less than or approximately 1 in water or other fluids found in a bodylumen, such that light part 12 (typically without heavy part 30 attachedto it) may float in body fluids or other fluids, such as water. In someembodiments light part 12 may be weighted for example evenly around oneor more of its internal axis so that when it floats in a liquid it maynot favor a particular orientation, but may rotate or otherwise moverelatively freely in surrounding water or other fluids. In someembodiments, light part 12 may be weighted, or may have components orweights or lighter parts arranged in such a manner (e.g., a ballast onone end and/or a gas reservoir or other light unit on, for example, theopposite end), to favor a particular orientation so that it may forexample return to a favored orientation even after it is moved orrotated away from such favored orientation.

In some embodiments, light part 12 may have s specific gravity of forexample, less than 0.9 or less than 0.7. In some embodiments, heavy part30 may have s specific gravity of for example, greater than 1.1 orgreater than 1.3.

In some embodiments and in an initial state when for example device 10may be ingested or otherwise inserted into a body, light part 30 andheavy part 12 may be temporarily attached to each other and device 10may therefore assume a non-buoyant configuration. In some embodiments,device 10 may be propagated or moved passively by way of peristalsis orotherwise through a body lumen such as for example the stomach or smallintestine, in such non-buoyant configuration.

In some embodiments, at a particular time, or at a particular point in abody lumen or in response to for example a signal, environmentalcondition and/or parameter that may be sensed by one or more sensors orthe passage of time, light part 12 may separate or detach from heavypart 30 and light part 12 may assume a buoyant or floatingconfiguration. In some embodiments the detaching of light part 12 fromheavy part 30 may occur or be initiated for example at or near the pointwhere device 10 approaches or enters the cecum, a small sac-likeformation before the colon. Other points for such detaching or releasemay be designated and may be achieved. In some embodiments, theconfiguration, weight or specific gravity of device 10 before heavy part30 may be detached from light part 12 may cause device 10 to settle forexample in or near the cecum, where the detachment of heavy part 30 fromlight part 12 may take place.

A detached heavy part 30 may in some embodiments continue sensing orcollecting data and possibly transmitting data to an external receiver105. In some embodiments detached heavy part 30 may be excreted from abody by, for example, peristaltic contraction or due to other natural orother processes.

External from the device 10 an external receiver 105 may receivesignals, for example, wireless signals from device 10. Reception may beaccomplished via a radio frequency (RF) wireless channel. Other suitablemethods of reception may be possible. Storage unit 125 may store signalsreceived by external receiver 105, for example, image data, sensor data,control data, etc. Processor 120 may process data, for example, toperform analysis and to display, for example, on a display 115. Externaltransmitter 110 may transmit control signals or other signals to device10. Transmitter 110 may be a RF transmitter, an ultrasound transmitteror other suitable transmitter. Transmitter 110 may be used to externalcontrol device 10, for example, to control the detaching of light part12 and heavy part 30. Transmitter 110 may be used to control otherfunctionalities of device 10.

Reference is made to FIG. 2, a schematic illustration of an area of anin-vivo sensing device where a heavy part and a light part of suchdevice may be connected. In some embodiments, light part 12 and heavypart 30 may be attached for example along a surface 200 which may insome embodiments be near or include an end or pole of light part 12.Surface 200 which may be for example along the edge of light part 12,may in some embodiments be convex so that when heavy part 30 may bedetached from light part 12, light part 12 assumes or retains a capsuleor oval shape. Surface 200 along the edge of heavy part 30 that may beclose to light part 12 may be concave or in a half moon shape so that isfits smoothly into light part 12. Other shapes such as for example awave that alternates between convex and concave, are possible and otherplanes along which heavy part 30 and light part 12 may be attached arepossible.

Heavy part 30 and light part 12 may be attached or releasably and/ordetachably held together by a fastener 202 such as for example glue,fuses, wires, magnets or other fastening means or combination offastening means that may detachably hold and then later release heavypart 30 from light part 12. Detachably holding may mean for exampleholding an item until such time as the hold is released or until atrigger, event or condition may facilitate the release of the item.

In an exemplary embodiment of the invention, fastener 202 may be freedor is may release a releasably held item such as for example heavy part30, in response to, for example, a signal or in response to the passageof time or in response to one or more environmental conditions. Forexample, fastener 202 may be or may include a wire or filament such asfor example a fuse or heat sensitive or degradable filament. In someembodiments, in response to a signal, heat may be applied to or acurrent may be passed through fastener 202 such as for example a heatsensitive filament or fuse, and heat sensitive filament or fuse may meltor degrade, freeing or allowing the detaching of heavy part 30 fromlight part 12. In some embodiments of the present invention heat, anelectrical charge, or a force may be applied to a fastener 202 by forexample wires 204 connected to power source 32 or power source 25 orsome other power supply.

In some embodiments fastener 202 may be for example one or more magnets,magnetized materials or materials that are responsive to anelectromagnetic force. Upon or in response to a signal, or at othertimes, such magnets may be deactivated or otherwise released, by forexample reversing the polarity of an electromagnet and/or changing thedirection of the electromagnetic field, thereby freeing or detachingheavy part 30 from light part 12.

In still other embodiments, fastener 202 may be a degradable filament orglue that may degrade over the course of, for example, the several hoursor other time period in which device 10 may be in a body before itreaches a designated body lumen such as for example the large intestine.In some embodiments such period may be from 6 to 8 hours. Suchdegradation may be precipitated by for example exposure to bodytemperatures, exposure to certain liquids, pH levels or other elementsor conditions as may be present in a body lumen. In some embodiments thethickness or other characteristics of a fastener 202 such as for examplea degradable filament or glue may be configured to degrade over a periodof time that may approximate the period required for device 10 to travelor be moved from for example the mouth to for example the cecum or someother desired location. Other configurations may be possible and othertime periods or degradation triggers or criteria may be used.

Other methods or processes for releasing fastener 202 such as forexample by the release of a chemical that may degrade fastener 202, fromfor example a portion of light part 12 or heavy part 30 along forexample surface 200, are possible. In some embodiments, heavy part 30 orlight part 12 may encapsulate medicaments or other materials that may bereleased when heavy part 30 detaches from light part 12. In otherembodiments of the present invention, heavy part 30 may not detach andmay instead release encapsulated material, e.g. degradable material,medicaments, or independent component. In some embodiments of thepresent invention, emptying attached heavy part 30 may enable device 10to become substantially buoyant. As such heavy part 30 may not bedetachable.

The detaching of heavy part 30 from light part 12 may in someembodiments be precipitated or initiated by for example a signal. Insome embodiments, a signal may be generated by for example circuitry 34or ASIC transmitter/controller 26. In some embodiments, a signal may begenerated for example in response to a timer 208 or counter that may beincluded in for example circuitry 34 or ASCI transmitter/controller 26or elsewhere, and such timer may be set to generate a signal after forexample the lapse of time that may approximate the amount of timerequired for device 10 to proceed from for example the mouth to forexample the cecum. Other time periods are possible. In some embodimentstimer 208 may be activated when for example device 10 is ingested orwhen for example device 10 is removed from its packaging prior toingestion. In other embodiments timer 208 may be activated upondetection of a is specified site in the GI tract.

In some embodiments a signal may be initiated from a source external todevice 10 such as for example a transmitter located outside of a body.Such signal may be received by or may otherwise affect a component ofdevice 10. For example, device 10 may include a receiver 26 that mayreceive a signal from a transmitter outside of a body. Such receiver 26may initiate for example a pulse of heat, electricity or magnetic chargeto release fastener 202, thereby detaching heavy part 30 from light part12. In other embodiments a signal may be generated by, for example, anultrasound transmitter and/or mechanism that may be located outside of abody and that may direct ultrasound waves towards a fastener 202, suchas for example a filament that is sensitive to ultrasound waves. Othersignals that may precipitate a release of fastener 202 and the detachingof heavy part 30 and light part 12 are possible. In some embodiments,ultrasound waves may be directed at device 10 or heavy part 30 and suchultrasound waves may detach or otherwise break apart heavy part 30. Inother embodiments, a part of heavy part 30 may disintegrate, dissolve orotherwise degrade thus releasing it from light part 12.

In some embodiments the sensors or sensing devices of device 10 may,until heavy part 30 separates from light part 12, be inactive, set tooff or may operate at a reduced rate or under reduced power consumptionlevels. In an exemplary embodiment, the detachment or separation ofheavy part 30 from light part 12 may trigger or serve as a signal fordevice 10 to activate, change functionality, or turn on, or for one ormore sensors of light part 12 to begin collecting sensory data such asfor example images. The turning on of device 10 or of sensors in lightpart 12 that may begin for example with the separation or detachment ofheavy part 30, may for example preserve the power available to lightpart 12 in, for example, power supply 25 so that sufficient powerremains in such power supply 25 or in light part 12 to power sensors andcollect sensory data from body lumens, such as for example some or allof the large intestine wherein light part 12 may be set afloat.

Reference is made to FIG. 3, a schematic illustration of an in-vivodevice with a photodiode switch and a detachable portion in accordancewith an exemplary embodiment of the present invention. The device 10depicted in FIG. 3 may include, for example, a switch 300 such as forexample a photodiode switch on or near surface 200 and an illuminationdevice 302 such as for example a light emitting diode (LED) that mayalso be situated on or near, and facing surface 200. In some embodimentsswitch 300 may be situated in light part 12 and illumination device 302may be situated in heavy part 30. In other embodiments, switch 300 andillumination device 302 may be situated elsewhere in device 10 and maybe connected to for example power source 32 and/or power source 25. Insome embodiments, surface 200 may be made for example from a transparentmaterial or may otherwise be transparent or semi-transparent to thelight emitted by illumination device 302. In some embodiments of thepresent invention, illumination device 302, not be incorporated intodevice 10 and may be external to the body lumen, for example, may beplaced over the skin such that light from illumination device 302 maypenetrate through the skin, for example, illumination device 302 may bepositioned directly over the cecum and the light may be detected byphotodiode switch 300. In one example, photodiode switch 300 may triggerone or more components in light part 12 and/or heavy part 30 to, forexample, activate.

In some embodiments, in response to a signal such as for example asignal from a counter such as for example timer 208 or another suitablecounter or another suitable signal, illumination device 302 may emitlight or otherwise signal switch 300 with for example light that may bedetected by switch 300. Such signal as received by switch 300 maytrigger, activate or otherwise turn on one or more sensing devices orother components of light part 12 or device 10. A counter such as forexample timer 208 may also signal a power source such as for examplepower source 25 or power source 32 to provide a pulse of for example,heat or electricity that may release or burn fastener 202 such as forexample wires, fuses or filaments, thus detaching heavy part 30 fromlight part 12.

In some embodiments of the present invention, imager 24, optical system22, and/or illumination 23 may be positioned away from viewing window 21as compared to corresponding components shown, for example, in FIG. 1.The volume between, for example, imager 24 and viewing window 21 mayserve as the additional volume that may be required to decrease thespecific gravity of light part 12 as may be described herein and mayalso serve to increase the viewing area on viewing window 21 that may bedefined by viewing lines 11 (compare to the field of view of FIG. 1), sothat imager 24 may capture, for example, more the periphery of bodylumen.

Reference is made to FIG. 4, a schematic illustration of an in-vivodevice 400 with one or more sensors, a photodiode switch and adetachable part in accordance with an exemplary embodiment of theinvention. Device 400 may be an in-vivo sensor that includes adetachable lobe, such as a heavy part 404, and a light part 402. Lightpart 402 may include one or more sensors such as for example one or moreimagers 410 that may be located for example on opposing ends or sides oflight part 402. One or more viewing windows 21 may be provided toenable, for example, capturing of images of the body lumen. Other oradditional sensors may also be included, and sensors may be situated onother parts of light part 402. One or more sensors such as for exampleimaging sensors in light part 402 may include one or more illuminationelements 406 and an optical imaging system that may include for examplea lens 408 and an imager 410 such as for example a CMOS imager. Lightpart 402 may in some embodiments also include a counter 412 that mayinclude for example a timer. Counter 412 may be capable of tracking thetime that has elapsed since a certain event such as for example theintroduction of device 400 into a body or some other event. Counter 412may be connected to illumination device 406 or other components ofdevice 400 by for example wires 411 or other circuitry. In alternateembodiments wireless communication may be possible between differentcomponents within device 400.

In some embodiments, heavy part 404 of device 400 may be attached tolight part 402 by way of for example fasteners 414. Fasteners 414 maybe, include or rely upon for example wires, fuses, such as for exampleburnable fuses, filaments, such as for example degradable filaments,glue, magnets or other items that may detachably or releasably holdheavy part 404 onto for example a fixed position of light part 402.Heavy part 404 may partially obstruct or overlap one or more of theviewing windows 21. Heavy part 404 may in some embodiments include apower source 416 such as a battery or other power source, a switch 418that may be part of or included in for example a photodiode sensor orother light-sensitive sensor, and wiring 420 that may connect or linkpower source 416, switch 418, fasteners 414 or other components.Alternatively, the components may be connected through a wirelessconnection, such as by microwave, blue tooth communication, etc.

In some embodiments, a signal may be generated by for example counter412, and such signal may activate, for example one on more ofillumination devices 406. Illumination devices 406 such as for examplethose that face heavy part 402 may have been off or inactive until suchsignal was generated. In response to a signal, one or more ofillumination devices 406 may emit light. Such light pass through aviewing window 21 and may be detected by for example a photosensitivesensor or switch 418. In response to the light that it detects, forexample from illumination device 406, switch 418 may signal for examplepower source 416 to apply for example heat, electricity or some otherforce to release fasteners 414. The release of fasteners 414 may detachor free heavy part 404 from light part 402.

In some embodiments the signal from for example counter 412 or someother source may be generated in response to the passage of time, suchas for example the passage of the approximate time that may lapsebetween the ingestion of device 400 and its arrival at a particular bodylumen or organ such as for example the colon or cecum (e.g., 6-8 hoursfrom ingestion, or other suitable time periods). In other embodiments, asignal may be generated in response to other events or stimulus that mayoccur or be provided from inside device 400 or from sources external todevice 400.

According to some embodiments of the invention there is provided amethod for sensing a lumen such as, for example, the large intestine. Amethod according to one embodiment is schematically described in FIG. 5.In one embodiment an in-vivo sensing device which may include, forexample, a floatable part and a non floatable part which may bereleasably connected, may be inserted into a patient's GI tract (502),typically by ingestion. According to one embodiment, the in-vivo sensingand or imaging device, may be activated or not upon ingestion. Accordingto some embodiments, activation of the device may be achieved, forexample, as described herein. After a time period which may beindicative of the device having arrived at designated location, e.g.,the patient's cecum (e.g., 6-8 hours after ingestion) the floatable andnon floatable parts may be caused to become detached from each other(504). According to some embodiments a signal may be generated which maytrigger or cause the two parts to become detached. According to someembodiments the detachment may be caused in response to indicationsother than time. For example, a motion detector, which may be includedin the device, may indicate, by showing the device may not be in motionthat the device has arrived in the cecum and a signal may then begenerated to cause detachment. Other suitable destinations or markerpoints, other than the cecum, may be used. Further, other lumens, otherthan the large intestine, may be targeted. Upon detachment of the twoparts the floatable part, which may include in-vivo sensingcapabilities, may be activated (506) thus enabling the floatable part,which will be easily transported through at least parts of the largeintestine, to sense (e.g., in one embodiment image) the large intestine.In alternate embodiments, other parts, such as a non-floatable part, maybe activated for sensing.

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated that many variations,modifications and other applications of the invention may be made whichare within the scope and spirit of the invention. The scope of thepresent invention is defined by the claims.

1. An in-vivo sensing device comprising: a first part having a firstspecific gravity; and a second part having a second specific gravity,wherein the first part and the second part are detachable.
 2. Thein-vivo sensing device according to claim 1 wherein the first specificgravity is greater than the second specific gravity.
 3. The in-vivosensing device according to claim 1 wherein the second specific gravityis less than the specific gravity of a bodily fluid within a body lumen.4. The in-vivo sensing device according to claim 1 comprising an imagerand an illumination source.
 5. (canceled)
 6. The in-vivo sensing deviceaccording to claim 1 comprising a filament to temporarily attach thefirst part to the second part.
 7. (canceled)
 8. (canceled)
 9. Thein-vivo sensing device according to claim 1 comprising a magnet, totemporarily attach the first part and the second part by anelectromagnetic force.
 10. (canceled)
 11. (canceled)
 12. (canceled) 13.The in-vivo device according to claim 1 wherein the first part isconfigured to detach in-vivo.
 14. (canceled)
 15. (canceled) 16.(canceled)
 17. The method according to claim 38 wherein the device isweighted such that it favors a certain orientation.
 18. The methodaccording to claim 38, wherein the first part is attached to the secondpart by an electromagnetic force.
 19. The method according to claim 18comprising changing the direction of the electromagnetic force. 20.(canceled)
 21. The method according to claim 38 comprising activating acomponent in the second part.
 22. The method according to claim 38wherein the component comprises an imager.
 23. (canceled)
 24. (canceled)25. The method according to claim 38 wherein the first part and thesecond part are attached with a filament.
 26. (canceled)
 27. (canceled)28. (canceled)
 29. (canceled)
 30. The method according to claim 38wherein the detaching is initiated by a signal external to the in-vivosensing device.
 31. A system for in-vivo sensing comprising: an in-vivosensing device comprising: a first part having a first specific gravity;a second part having a second specific gravity, wherein the firstspecific gravity is different from the second specific gravity and thefirst part and the second part are attached by a releasable fastener;and an external receiver to receive wireless signals from the in-vivodevice.
 32. The system according to claim 31 comprising an in-vivoimager.
 33. (canceled)
 34. The system according to claim 31 comprisingan external transmitter for transmitting signals to the in-vivo device.35. (canceled)
 36. (canceled)
 37. The system according to claim 31comprising a display to display sensed data from the in-vivo sensingdevice.
 38. A method for in-vivo sensing comprising: detaching a firstpart of an in-vivo device located in an in-vivo body lumen from a secondpart of the in-vivo device, wherein the first part is floatable in thegastrointestinal tract and the second part is not floatable in thegastrointestinal tract; and activating a component in the first part.39. The method of claim 38 comprising: sensing a parameter; anddetaching the first part from the second part in response to sensing theparameter.